Process of making toned printing-plates.



M. A. DROITGUR. PROCESS 0I MAKING TONBD PRINTING PLATES.' APPLICATION211.111) APE. 16, 1'910.

985,664. yPatented Fenzs, 1911.

WN W W @i k ivi/7- /mg bL7-'.57 Y 5 J 7 Wm/m/// //7/] .UNITED STATESvPATENT oFFIcE.

MICHAEL DROITCO'UR, OF CHICAGO, ILLINOIS, ASSIGNOR TO MIEHLE PRINTINGPRESS AND MANUFACTURING COMPANY, F CHICAGO, ILLINOIS, A CORPORATION 0FILLINOIS..

PROCESS 0F.1VIAKING TONED PRINTING-PLATES.

- Specification of Letters Patent Patented Feb; 28, 1911.

Application filed April 16, 1910. .Serial No. 555,830.

1 State of Illinois, have invented certain new and useful Improvements`in Processes of Making Toned Printing-Plates; and I hereby declare thatthe following is a full, clear, and exact description thereof, referencebeing had to the accompanying drawings, which form part of thisspecification.

This invention is an improvement in the art of making made-ready ortoned printing plates, in which the desired lights and shades in theimpression taken therefrom are obtained by varying the surface of theprinting plate itself, so as to obtain greater pressure at the pointswhere the darker prints are desired and less pressure at the pointswhere lighter impression is desired. i y.

The object of the present invention 1s to produce the desired tones inthe printing plate during the process of making the shell or surface ofsuch plate, so that the printing surface of the shell will be tonedprior to the completion of the making of the shell and at a time when itwill'be possible to effect the toning with the least possible distortionof the metah and whereby the most delicate variations in tone can beobtained .ence to the accompanying drawings Which illustrate variousstepsin my novel method of preparing a toned printing plate, and willenable'any one familiar with the art to practically utilize theinvention; and I refer to the claims for summaries of the novel featuresand 4steps in the process for Which protection is desired.

Figure 1 is a fl'agrammatical elevation of an original printing surfaceor type form, and a Wax sheet and backing preparatory to forming themold or matrix` in the wax from such surface. Fig. 2 is a diagrammaticalview of a Wax mold or matrix Witli'a metallic skin or partially formedvery thin shell' depositedthereon. Fig. 3 illustrates diagrammaticallythe toning of this skin or partly formed shell. Fig. l illustratesdiagrammatically the complete toned shell i.

formed by depositing additional metal upon the toned skin. Fig. 5 shows'one Way et backing' up such shell tov forin a printing plate. Fig. 6 isa diagammatical sectional view of a finished printing plate.

In one method embodying the invention a wax mold or matrix is formed inthe ordinary way, as for instance by ini wes-'ing' a sheet of wax -VVattached to a suiml ie backing fw, upon a printing surface`or type formT which may rest upon a suitable bed. By the termv Wax I intend toinclude any suitable material which is ordinarily used, or may be used,for receiving 1an intaglio irnpression from the printing surface, andupon which may be subsequently deposited a metallic shell, as indicatedat S, Fig. gt. The means for and mode of forming such shellsas byelectrotyping-being wellknown, requires no description herein.

In accordance With my invention after a thin skin of metal has' beendeposited upon the face of the'jvax matrix, as indicated at s in Fig. 2,the depositing of metal on the mold is'suspended and this skin is tonedby impressing the ,wax matrix and skin on the form after a previouslyprepared overlay O has been placed on the form as indicated in Fig. 3.Said overlay may be .of any Well known or desired construction,-forinstance an etched vzinc plate, or a chalk overlay, or a cut paperoverlay, which are now commonly used; and well understood in the art.The overlay being constructed so as to be thinner at placescorresponding to those portions of the printing surface which it isdesired shall have less pressure during Y the taking of an impression;and thicker, at the places corresponding to the portions.

loo

of the printing plate which it is desired shall the wax matrix and themetal skin s deposited thereupon are toned in accordance With theoverlay O, so that the surface of the wax matrix, and the skin s insteadQf remaining absolutely plane surfaced, is 'depressed, more or less,where it contacts with projections on the overlay and in accordance nwith the size and thickness of 'such projec tions.

The thus f toned Wax mold and metal skin thereon, are then removed fromtheform and additional metal deposited upon the skin in the usual mannerto form with or convert such skin into a metal shell S (Fig. 4) of'theusual thickness.

On account of the previous toning 7 of the skin as described,' thecompleted shelly printing surface,-siich surface being already toned inaccordance with the overlay. It Will be observed that the tones of the iplate are determined and 'formed before the shellv is completed, so thatthe shell itself does not have to be distorted after formation in orderto tone ita-noi' does the completed plate have to be distorted in orderto tone it.

The plate may be backed in various ways; as indicated in the drawings,Fig. 5, I prefer to lay the shell face downward upon a suitable bed BWithin a chase C, and `pour suiiicient molten metal M into the chase toform a plateof the desired thickness. After the metal is set the plateis removed and reduced to proper thickness, and plane siii'- facedl onthe back, by removing any surplus metal; as by planinlr it along theline m Fig. 5; the resultant J ate after itsedges are trimmed being reay for printing, as indicated in Fig. 6. Of course the thin metal skin sbecomes an integral and indistinguishable part of the shell S, and Ihave simply illustrated it diagrammatically in the drawings tofacilitate t-he explanation of the inveiit-ion.

I preferably support the face of the shell Swhile applying` the backinoM thereto and While planing the back of1 the plato, by means of anoverlay U, Fig. 5, as described in my Patent No. 952,312 of March 15th,1910, in order to prevent any .distortion of the shell by the Weight andheat of the molten metal poured thereupon to back it, or the distortionof the printing surface by the pressure of the planers or grinders usedto reduce the plate to the desired thickness, and its back to a uniformplane surface.

Butthis overlay in the present instance is not, used in an sense to tonethey plate, the toning beingge ected as above described during theformation, but prior to the coiiipletion of, the thin type surface orshell.-

Having described my invention what I,

claim is: l

- v1. The herein described method of making toned shells for printingplates, consisting' in forming a matrix, producing a skin of inetal onthe face of the matrix, toning the skin of metal by pressing the sameagainst a suitable toning surface, and then supplying sufficient metalto the toned skin to form a shell. i

The herein described method of making' toned printing plates consistingin forming 3. The liereindescribed method of making toned printingplates, consisting in deposit'- ing a thin skin of metal upon a suitablemold or'inatrix, toning the matrix and skin by pressing same against anoverlay; then depositing additional metal 'to the skin to form a shell;and subsequently backing such toned slill to form a printing plate.

4. 'Ihe herein described method of making toned shells for printingplates, ctnsisting in taking an impression on a Wax sheet to form amatrix, depositing upon this matrix a skin of metal, toning this skin byimpressing it while on the matrix against a suitably prepared toningirsurface, and thickening the skin to form a shell by depositingadditional metal thereon. f

5. The herein described method of making .toned print-ing plates,consistingin taking an impression on a Waxsheet to form a ina-A trix,depositing upon this matrix a skin of metal, toning this skin byimpressing it while on the matrix against a suitably prepared toningsurface, thickening the skin to form a shell by deposit-ing additionalmetal thereon; and subsequently backing the toned shell-to formaprinting' plate, substantially as described'.

6. The herein described nietliod of making toned printing plates,consisting first in making a matrix by impressing a plastic sheet upon aprinting surface, depositing a skin of metal upon the matrix; placing asuitably prepared overlay upon the printing sur face and pressing the`matrix With its skin of metal against the overlay upon the printingsurface; then backing the toned skin to forni the plate. 7. The hereindescribed method of making toned printing plates, consisting in takingan impression from a printing surface upon a wax sheet, depositing askin of metal upon the impressed surface of the Wax sheet; placing asuitably prepared overlay upon the printing surface and pressing the waxsheet with its skinof metal against such overlay, then depositingadditional. metal upon-"the toned skin to form a shell, and finallyremoving the wax sheet and applying a suitable backing to thetonedshell.

K 8. The herein described method of making toned printing platesconsisting in taking an impression on a Wax sheet to form a matrix,

- depositing upon this matrix a skin of metal,

toning this skin by impressing it While on the matrix against asuitablyprepared toning surface; thickening the skin to form a shell bydepositing additional metal thereon; applying sulicient metal to theback of the toned shell to form a printing plate, and

finally trimming the finished plate.

9. The herein described method of'making toned printing plates,consisting in taking an impression from a printing surface .upon

a wax sheet,.depositing a slfin of metal upon the Wax sheet; placing asuitably prepared overlay upon the printing surface and pressing the Waxsheet.with its skin of metal agai st such overlay; then depositingadditional" metal upon the toned skin to form a shell; removing theWaxsheet;- applying an underlay to the face of the shell to preventCopies of this patent may be obtained for -of the shell -to form a bypressing 'same against a suitable toning surface; depositing additionalmetal on the toned skin to form a shell; placing the toned shell facedownward on a suitable support, applying an underlay to the fa ce of theshell to prevent distortion thereof during the backing of the shell;applying metal to the back of the shell to form a plate; and finallyreducingthe plate to the desired thickness while the face of the shellis supported by 4the underlay, substantially asdescribed.

In testimony that I claim the foregoing as my own, I aiiix my signaturein presence of two Witnesses.

MICHAEL A. DROITCOUR.

Witnesses AELMER HASSMANN,

SYLvIA WILLS.

ve cents each, by addressingthe Commissioner of Yaten'ts, Washington, D.C.

